Prior to the present invention ophthalmic viscosurgery utilized solutions of fractionated sodium hyaluronate. The surgical uses of the latter composition are described in U.S. Pat. No. 4,141,973 (Balazs); in the article Pape, L. G., Balazs, E. A. "The Use of Sodium Hyaluronate (Healon) in Human Interior Segment Surgery" Ophalmology 87:699-705 (1980) and in the text Healon (sodium hyaluronate) A Guide To its Uses In Ophthalamic Surgery, D. Miller and R. Stigmann (John Wily & Sons). The succinylated collagen solutions of the present invention find utility in surgery as a replacement for such sodium hyaluronate solutions.
Succinylated collagen compositions are known and have been used in contact lenses, U.S. Pat. No. 4,223,984 (Miyata el al), in skin or wound dressings, U.S. Pat. No. 4,294,241 (Miyata), and in thin membranes suitable for ophthalmic drug delivery, U.S. Pat. No. 4,164,559 (Miyata et al). Stabilized collagen gels made from purified tropocollagen have been used as replacements for vitreous in rabbit and monkey eyes. Stenzel, K. H., Dunn, M. W., Rubin A. L. and Miyata, T. "Collagen Gels: Design for a Vitreous Replacement", Science, June 13, 1969 vol. 164 pp. 1282-1283. These unmodified collagen gels, however, proved deficient for they became opaque under pH conditions found within the eye.